1. Field of the Invention
The invention relates to a portable or notebook computer system capable of being docked to an expansion base unit, and more particularly, to a motorized expansion base unit for ejecting the notebook computer when a resource conflict is determined upon docking.
2. Description of the Related Art
A development in the computer field is the expansion base system to which a portable or notebook personal computer can be docked. The expansion base unit, which is typically located in the user's office or home, includes connectors for connection to CRT display monitors, ISA expansion cards and other peripheral devices. Since the housing of a notebook computer is rather limited in size, only a limited number of device controllers and connectors can be fitted into the notebook computer. Thus, by providing a means of connection to a notebook personal computer, the expansion base unit allows the notebook computer to take advantage of the additional devices connected to the base unit.
The notebook computer has previously been inserted into the expansion base unit by manually pushing the notebook computer into a connector provided in the base unit. To remove the notebook computer from the base unit, the user typically must either pull on the notebook computer itself or push an eject button. The notebook computer typically must be in an "OFF" state before the notebook computer can be properly inserted into the expansion base unit. If the user forgets to place the notebook computer into the "OFF" state, certain problems may arise. When a notebook computer in an improper state is inserted into the expansion base unit, the notebook computer will be unaware that it has been docked at the expansion base unit and thus will be unable to communicate with the base unit, or the notebook computer may be rebooted, resulting in potential data loss.
More recently, a motorized expansion base unit has been developed. Such a system is described in patent application Ser. No. 08/188,554, entitled "Method and Apparatus for Sensing and Changing the State of a Computer Before Connecting the Computer to or Disconnecting the Computer from an Expansion Unit," which is assigned to the assignee of the present application, and which is hereby incorporated by reference. This motorized expansion base is not prior art to the present invention, as the present invention was developed concurrently and for use with this motorized expansion base. This description is provided in this section to help provide an overview of the specific problem addressed by the present invention.
The motorized docking method is generally similar to the loading of a tape into a VCR. The user pushes the notebook computer into a slot in the docking base unit. In response to the pressure, the docking base unit causes the motor to grip the notebook computer and to pull it into position for connection to the docking connector. The motorized expansion base unit is designed to refuse the docking or undocking requests of a notebook computer until the notebook computer is placed into a proper state. Thus the user would be forced to place the notebook computer into the proper state before the expansion base unit will accept the notebook computer, thereby avoiding any communication or data loss problems.
In addition, the system described in the referenced patent application utilizes an operating system according to the Plug and Play specification developed by Microsoft Corp., Intel Corp., Compaq Computer Corp. and Phoenix Technologies, Ltd. One feature of a Plug and Play computer system is that expansion devices connected to the computer system can be configured at run time. This enables a notebook computer to be docked to the expansion base unit while the notebook computer is in STANDBY mode. In STANDBY mode, most of the components in a computer system are off. The only components kept active are those necessary to store the state of the computer system. Since the notebook computer can be reconfigured by the operating system, the notebook computer need not be rebooted to allow it to recognize the expansion base unit. As a result, user convenience is enhanced, since much more time is required for a computer system to reboot than to exit from STANDBY mode. For a detailed description of the Plug and Play specification, refer to Plug and Play ISA Specification (1994), Intel Corporation and Microsoft Corporation and Plug and Play BIOS Specification (1993), Compaq Computer Corporation, Phoenix Technologies Ltd., and Intel Corporation. The specifications are hereby incorporated by reference.
Another problem associated with docking a notebook computer to an expansion base unit is that the notebook computer and the expansion base unit may have bus devices having resource conflicts. The expansion base unit is capable of receiving various bus card peripheral devices, some of which may conflict with certain resources of the peripheral devices contained in the notebook computer. If the notebook computer is docked without resolving the conflicts, a fatal error may occur if the conflicting resources are utilized. The typical user has no way of knowing in advance whether such a conflict may occur. Thus, it is desirable that a method be developed to identify such conflicts and to prevent the docking of the notebook computer to the expansion base unit when such a fatal level of conflict occurs.